PENG Jian-wen, ZENG Fei-tao, LI Chang-hong, et al. Experimental study of anisotropy and mechanical property of quartz sandstone[J]. 2017, 38(S1): 103-112.
DOI:
PENG Jian-wen, ZENG Fei-tao, LI Chang-hong, et al. Experimental study of anisotropy and mechanical property of quartz sandstone[J]. 2017, 38(S1): 103-112.DOI: 10.16285/j.rsm.2017.S1.012.
Experimental study of anisotropy and mechanical property of quartz sandstone
To investigate the effect of bedding on failure mode
elastic modulus and strength of rock with high porosity under different stress conditions
several groups of triaxial tests on specimen with different bedding angles are conducted with pre-hydrostatic compression and axial stress increasing mode. The results show that the anisotropic quartz sandstone showed different characteristics of deformation damage under different stress conditions. With 30 MPa as dividing line of confining pressure
shear failure mode happened in the range of low confining pressure and as the confining pressure increased
fracture surface turned slope to horizontal and is influenced by the bedding. In range of high confining pressure
under the influence of bedding
failure mode could be divided to shear yield and volumetric yield. As the confining pressure increased
the number of newly closed crack reduce
the effect of anisotropy to elastic modulus showed reducing trend and the average increasing rate of Young’s modulus decreased. Young’s modulus of all specimen declined at bedding angle = 60°. Strength curves of different specimen with different bedding angles showed U shape. The minimum compressive strength in range of 0-20 MPa confining pressures showed at the bedding angles = 30°; while in 30-60 MPa transferred to = 45°. Feature coefficient of compressive strength for quartz sandstone with different bedding angles decreases as the confining pressure increases
and keep constant as confining pressure is over 30 MPa.